The impact of psychological expert testimony in child sexual abuse cases
Crowley, MJ (1994) The impact of psychological expert testimony in child sexual abuse cases. PhD thesis, University of Tasmania.
While the admissibility of psychological expert testimony varies from one
common law country to another, evidentiary analyses dealing with the impact of such
testimony are invariably opinion-based and lack empirical support. Predictions
from theoretical models of communication/persuasion processes suggest that
psychological expert testimony in child sexual abuse cases may be given considerable
weight by jurors, but the experimental literature investigating the impact of such
testimony is scant.
This thesis reports four experiments designed to investigate the juridical impact
of psychological expert testimony in a simulated child sexual abuse case, using
gender-balanced juries throughout. In the first study, presence or absence of a
psychologist's generalised testimony concerning children's cognitive abilities was
varied across three ages of child victim/witness. Subjects viewing the expert
testimony rated the child higher on memory ability, resistance to suggestion and
reality monitoring ability and gave higher ratings of defendant guilt.
In the second experiment, the same expert testimony was presented by male and
female experts in either an adversarial or nonadversarial role. Significant
interaction effects indicated that, for the male expert only, ratings of the dependent
variables were significantly lower in the adversarial role.
The third experiment investigated whether expert testimony presented before and
after the child's testimony is differentially utilized. Ratings of the child-based
variables and verdict ratings did not differ as a function of the sequence of testimony,
but regardless of temporal order, presence of expert testimony led to significantly
higher child-based ratings than the absence of such testimony.In the fourth experiment, the differential impact of three types of expert
testimony were studied; testimony concerning children's general cognitive abilities,
testimony concerning characteristic behavioural reactions to sexual abuse, and
testimony assessing the validity of the child's statement. The quality of the child's
statement was varied, using content-based criteria. Subjects viewing the cognitive
abilities testimony rated the child higher on memory, resistance to suggestion and
reality monitoring, but there were no significant differences on verdicts by type of
testimony. Those who viewed the child's enhanced statement gave higher ratings of
defendant guilt on the aggravated sexual assault charge. Results indicated greater
acceptance but less scrutiny of nonadversarial expert testimony.
In all four studies, the prime predictor of child credibility and verdict ratings
were the jurors' perceptions of whether the child had misinterpreted the defendant's
actions. Juror gender effects were also consistent in all studies, with females more
likely to rate the child's credibility higher and to find the defendant guilty.
In general, results indicated that psychological expert testimony which details
research findings concerning children's cognitive abilities seems less likely to
change verdicts than to increase the degree of certainty felt by those voting guilty,
and may therefore serve to improve the juridical decision-making process. The
impact of psychological expert testimony appears to vary with expert role when the
psychologist is male. Changing the order in which testimony is presented appears to
have no significant impact on verdicts or jurors' perceptions of the child witness.
The implications of the thesis findings for psychological theory and legal practice are
|Item Type:||Thesis (PhD)|
|Additional Information:||Copyright 1994 the Author|
|Deposited By:||Mrs RM Adams|
|Deposited On:||02 Aug 2011 13:01|
|Last Modified:||02 May 2013 13:56|
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